Front electronic shocks

[Don S]

New owner to a 2007 Tahoe ltz with z55. The ride is flat awful. Zero absorption of any roughness on the road.

The compressor is not running first of all and I’ve ordered another one. I’ve checked fuses as well. That looks straight forward on doing that but I’m clueless on this front electronic shock thing.

How can I check that juice is going to them? This thing rides sooo bad you’d have to be in it to believe it. I mean I would think I’d be getting some help from the springs if the shocks were dead but doesn’t feel like it.

It’s sitting down so hard it shimmies around when you’re driving. Any help is appreciated. Like I say I think the compressor to run the air shocks in the rear is understandable but I’m clueless on this front end.
Did I mention how bad it is riding? Guess I got the point across.
Thanks

 

[wjburken]

How many miles on your Tahoe?

 

[Don S]

How many miles on your Tahoe?

Man, I knew I was missing some info. She’s reading 215,000

 

[wjburken]

What do you know about the maintenance history on your Tahoe? There is a good chance your shocks are all used up. Question is, what do you have currently on your Tahoe.

Here is a good thread discussing the airride autolevel system:
https://www.tahoeyukonforum.com/threads/what-front-struts-have-i-got.112176/#post-1345766

There is a good chance that a previous owner replaced the Z55 suspension components with regular shocks to save money.

Do remember hearing the compressor ever run since you’ve owned it?

If you look at the top of your front shocks, do you see a wire plugged into it at the top?

Do your rear shocks look like they have an air bladder at the top with air lines running to them?

 

[Big Mama]

The compressor should come on for about 5 seconds when you turn the key to ON. Check the system over to see why the compressor failed. Could just be old or a hole or leak in one of the shocks or line caused the pump to run non stop.

 

[iamdub]

First off- do you have any suspension or Stabilitrak system warning lights on?

In a place where it's safe to experiment (no or very minimal traffic, no chance of abrupt maneuvers, etc.) that has some sharp bumps, unplug the wires from the shocks. The fronts will have them on the top in the center, the rears will be on the back sides of the bodies. Ignore the air lines for now but take note if the air bladders are torn (likely, they are).

Go for a slow test drive to see if the ride is improved. Don't make any sudden turns with the wheel because your Tahoe may feel very top-heavy and can get out of control. You only need to test the bump/shock absorption in a straight line drive.

If it's better, then your shocks are really worn and the computer has them firmed up to compensate.

You can either replace all with non electronic/non-air shocks and struts, or get air shocks with no electronic damping or get all direct OEM replacement parts and restore all systems.

 

[Don S]

What do you know about the maintenance history on your Tahoe? There is a good chance your shocks are all used up. Question is, what do you have currently on your Tahoe.

Here is a good thread discussing the airride autolevel system:
https://www.tahoeyukonforum.com/threads/what-front-struts-have-i-got.112176/#post-1345766

There is a good chance that a previous owner replaced the Z55 suspension components with regular shocks to save money.

Do remember hearing the compressor ever run since you’ve owned it?

If you look at the top of your front shocks, do you see a wire plugged into it at the top?

Do your rear shocks look like they have an air bladder at the top with air lines running to them?

No history. Compressor doesn’t run. Fuses are good. Wire connectors attached to front shocks. Yes rear has airlines going to them. Glovebox says it is Z55.
Thanks I have C0660 code that exhaust valve is faulty in compressor. My new compressor came in mail today. Hope this fixes rear at least.

 

[Don S]

The compressor should come on for about 5 seconds when you turn the key to ON. Check the system over to see why the compressor failed. Could just be old or a hole or leak in one of the shocks or line caused the pump to run non stop.

Compressor never comes on. I have C0660 code and suspension message on dash. Fuses are good New compressor came in mail today. 0660 code is exhaust valve bad in compressor.

 

[Don S]

How many miles on your Tahoe?

215.,000

 

[wjburken]

No history. Compressor doesn’t run. Fuses are good. Wire connectors attached to front shocks. Yes rear has airlines going to them. Glovebox says it is Z55.
Thanks I have C0660 code that exhaust valve is faulty in compressor. My new compressor came in mail today. Hope this fixes rear at least.

Sounds like a good first step.

Beware that there is a possibility of getting a face full of crap depending on how much dirt and road grime has built up. It is actually a pretty straight forward job swapping compressors.

 

[wjburken]

215.,000

I would start shopping and get prices on rear shocks and front struts. I’ve had good luck with Arnott for rear shocks.

 

[Rivelite]

I agree with the above.

Most likely the rear shocks are torn and don't hold air anymore, which in turn probably over time burned your compressor out trying to fill them. I recall a conversation with a Cadillac service tech a while back when I replaced my rear shocks and compressor as I also have the Z55 RPO. She said while the full function on the rear shocks is definitely the best when the shocks and compressor are working together, the only real function of the compressor is to keep the truck level at the calibrated ride height under various loads. She went on to explain that it would be better to have new air shocks with a non functioning compressor than a new compressor with the original shocks as the compressor would not improve the drive-ability alone. The fronts are a bit different than the rears as they do electronically adjust for a stiffer or softer ride as necessary as the rears are "conventional" and just have the added air bag in them.

After their quote of about 2300 for the rears set up only, I went with Arnott and did the job myself for about 700 for all 4 corners and a few hours labor in the garage. I decided to keep the truck stock and went with the air shocks in the back instead of going with conventional and overriding the dash light for the ride height sensor.


Good Luck

 

[Bigshawn]

I have a 2001 yukon slt with autoride. It still has the stock shocks on it but i had to replace the compressor at about 220,000. You can unhook the airline going into each rear shock and pump them up with your home air compressor to see if they have leaks or will hold air. My old compressor i could hear everytime it would pump up but the new one is very quiet, i never hear it run at all.

 

[Trailblazzin]

Not trying to highjack this thread but, I’ve replaced rear shocks and front struts with A/C Delco’s, they were considerably more expensive but wanted to keep it like it was.

One of the fronts was making a squeak so I replaced both as was always told to replace in pairs.

The rears were showing some serious wear on the bladder but wasn’t leaking but looked like they could at any time. So I replaced both of those as well.

Now it doesn’t take bumps/potholes very well, still handles good on corners and at highway speeds. Seems really harsh, do I need to reset something to account for new shocks/struts? Could one of the sensors be bad? I have NO dash lights or codes on.

I’m the second owner and have all previous service records and one of the struts and compressor was replaced under warranty a long time ago but nothing else appears to ever have been done. 120k miles now.

What should I try? Any suggestions?

 

[Big Mama]

Others will chime in but sounds like they may have overfilled. Does the rear look higher than normal?

 

[iamdub]

Not trying to highjack this thread but, I’ve replaced rear shocks and front struts with A/C Delco’s, they were considerably more expensive but wanted to keep it like it was.

One of the fronts was making a squeak so I replaced both as was always told to replace in pairs.

The rears were showing some serious wear on the bladder but wasn’t leaking but looked like they could at any time. So I replaced both of those as well.

Now it doesn’t take bumps/potholes very well, still handles good on corners and at highway speeds. Seems really harsh, do I need to reset something to account for new shocks/struts? Could one of the sensors be bad? I have NO dash lights or codes on.

I’m the second owner and have all previous service records and one of the struts and compressor was replaced under warranty a long time ago but nothing else appears to ever have been done. 120k miles now.

What should I try? Any suggestions?

You can try having the suspension controller reset to set the current ride at as it's "zero/base". This is a function for a dealer or someone with a TechII.

 

[Trailblazzin]

Others will chime in but sounds like they may have overfilled. Does the rear look higher than normal?

Sorry should have been more specific, the front seems to be the issue. Extremely stiff and harsh over bumps.

You can try having the suspension controller reset to set the current ride at as it's "zero/base". This is a function for a dealer or someone with a TechII.

I might have to look into a tech2, I avoid the dealer like the plague. Is that normal to have to do a reset after a strut/shock replacement?

 

[iamdub]

I might have to look into a tech2, I avoid the dealer like the plague. Is that normal to have to do a reset after a strut/shock replacement?

I can't say it's normal, but it's not farfetched and it'd be a good first step. The computer may just be still trying to firm up the old worn-out shocks. It doesn't know you have new ones. To see if it's the controller making the shock stiff, you can unplug the shocks and go for a short test drive. I recommend you do this on a street with no traffic and minimal turns. If your test road isn't immediately by your house, you can drive to it then unplug the sensors, reaching through the wheel wells. If it's much softer, then you can assume it's not defective shocks and it's likely just the computer needing a little help.

I don't know if the suspension controller is a separate computer altogether or if it's built into the PCM or BCM. If it's separate, you may be able to remove a fuse(s) to default it. Or disconnect the battery for a while.

If you do your own work on late model GMs, investing in a Tech2 might be worth it to you. I'd say there are at least five currently active members that have and regularly use one. James (@swathdiver) is one that could fill you in on the latest info and source. I spent about $200 on a really nice scan tool, but it's still just a one-way device. Had I known better, I absolutely would've spent an additional $100 and got a Tech2. But, the scanner I have is good for other, non-GM vehicles I may be servicing so it's not a total waste.

 

[Trailblazzin]

I can't say it's normal, but it's not farfetched and it'd be a good first step. The computer may just be still trying to firm up the old worn-out shocks. It doesn't know you have new ones. To see if it's the controller making the shock stiff, you can unplug the shocks and go for a short test drive. I recommend you do this on a street with no traffic and minimal turns. If your test road isn't immediately by your house, you can drive to it then unplug the sensors, reaching through the wheel wells. If it's much softer, then you can assume it's not defective shocks and it's likely just the computer needing a little help.

I don't know if the suspension controller is a separate computer altogether or if it's built into the PCM or BCM. If it's separate, you may be able to remove a fuse(s) to default it. Or disconnect the battery for a while.

If you do your own work on late model GMs, investing in a Tech2 might be worth it to you. I'd say there are at least five currently active members that have and regularly use one. James (@swathdiver) is one that could fill you in on the latest info and source. I spent about $200 on a really nice scan tool, but it's still just a one-way device. Had I known better, I absolutely would've spent an additional $100 and got a Tech2. But, the scanner I have is good for other, non-GM vehicles I may be servicing so it's not a total waste.

Ok, so should I unhook the sensors or the struts or both?

I’m going to look into a tech2 a little more seriously. I have to search around a little more and see where everyone is getting theirs.

 

[iamdub]

Ok, so should I unhook the sensors or the struts or both?

I’m going to look into a tech2 a little more seriously. I have to search around a little more and see where everyone is getting theirs.

Just unplug the electrical connectors on the top center of the struts. Don't do anything with the height sensors.